Hi, Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote: > Can you try to test with --bitmap=none, and --assume-clean(or echo > frozen to sync_action), let's see if spin_lock from wait_barrier() and > from md_bitmap_startwrite is bypassed, how performance will be. I did not notice that it was syncing disks in the background. It is much better now: READ: IOPS=1748K BW=6830MiB/s WRITE: IOPS= 749K BW=2928MiB/s Perf's output: + 98.04% 0.00% fio [unknown] [k] 0xffffffffffffffff + 97.86% 0.00% fio fio [.] 0x000055ed33e52117 + 94.64% 0.03% fio libc.so.6 [.] syscall + 94.54% 0.09% fio [kernel.kallsyms] [k] entry_SYSCALL_64_after_hwframe + 94.44% 0.03% fio [kernel.kallsyms] [k] do_syscall_64 + 94.31% 0.00% fio fio [.] 0x000055ed33e4fceb + 94.31% 0.07% fio fio [.] td_io_queue + 94.15% 0.03% fio fio [.] td_io_commit + 93.77% 0.05% fio libaio.so.1.0.2 [.] io_submit + 93.77% 0.00% fio fio [.] 0x000055ed33e74e5e + 92.03% 0.04% fio [kernel.kallsyms] [k] __x64_sys_io_submit - 91.86% 0.05% fio [kernel.kallsyms] [k] io_submit_one - 91.81% io_submit_one - 52.43% aio_read - 51.94% ext4_file_read_iter - 36.03% iomap_dio_rw - 36.02% __iomap_dio_rw - 21.56% iomap_dio_bio_iter - 17.72% submit_bio_noacct_nocheck - 17.09% __submit_bio - 14.81% md_handle_request - 8.34% raid10_make_request - 6.96% raid10_read_request - 2.76% regular_request_wait 2.58% wait_barrier 0.76% read_balance - 1.07% asm_common_interrupt - 1.07% common_interrupt - 1.06% __common_interrupt + 1.06% handle_edge_irq 2.22% md_submit_bio 0.51% blk_mq_submit_bio - 10.68% iomap_iter - 10.64% ext4_iomap_begin - 4.07% ext4_map_blocks - 3.80% ext4_es_lookup_extent 1.77% _raw_read_lock 1.68% _raw_read_unlock 3.51% ext4_set_iomap + 0.54% asm_common_interrupt - 1.21% blk_finish_plug - 1.20% __blk_flush_plug - 1.19% blk_mq_flush_plug_list - 1.15% nvme_queue_rqs + 1.01% nvme_prep_rq.part.0 - 6.04% down_read - 1.73% asm_common_interrupt - 1.73% common_interrupt - 1.72% __common_interrupt - 1.71% handle_edge_irq - 1.58% handle_irq_event - 1.57% __handle_irq_event_percpu - nvme_irq - 1.46% blk_mq_end_request_batch 0.80% raid10_end_write_request 0.55% raid10_end_read_request - 5.43% up_read + 0.99% asm_common_interrupt - 3.99% touch_atime - 3.87% atime_needs_update + 0.68% asm_common_interrupt - 39.00% aio_write - 38.78% ext4_file_write_iter - 28.16% iomap_dio_rw - 28.15% __iomap_dio_rw - 14.49% iomap_dio_bio_iter - 12.65% submit_bio_noacct_nocheck - 12.61% __submit_bio - 11.54% md_handle_request - 7.91% raid10_make_request 3.24% raid10_write_one_disk - 1.21% regular_request_wait 1.13% wait_barrier 1.14% wait_blocked_dev + 0.57% asm_common_interrupt 1.04% md_submit_bio - 8.05% blk_finish_plug - 8.04% __blk_flush_plug - 6.42% raid10_unplug - 4.19% __wake_up_common_lock - 3.60% _raw_spin_lock_irqsave 3.40% native_queued_spin_lock_slowpath 0.59% _raw_spin_unlock_irqrestore - 1.00% submit_bio_noacct_nocheck + 0.93% blk_mq_submit_bio - 1.59% blk_mq_flush_plug_list - 1.02% blk_mq_sched_insert_requests + 0.98% blk_mq_try_issue_list_directly - 4.53% iomap_iter - 4.51% ext4_iomap_overwrite_begin - 4.51% ext4_iomap_begin - 1.69% ext4_map_blocks - 1.58% ext4_es_lookup_extent 0.72% _raw_read_lock 0.71% _raw_read_unlock 1.54% ext4_set_iomap - 2.83% up_read + 0.92% asm_common_interrupt - 2.26% down_read + 0.57% asm_common_interrupt - 1.81% ext4_map_blocks - 1.66% ext4_es_lookup_extent 0.81% _raw_read_lock 0.70% _raw_read_unlock - 1.67% file_modified_flags 1.43% inode_needs_update_time.part.0 + 64.19% 0.02% fio [kernel.kallsyms] [k] iomap_dio_rw + 64.17% 2.41% fio [kernel.kallsyms] [k] __iomap_dio_rw + 52.43% 0.03% fio [kernel.kallsyms] [k] aio_read + 51.94% 0.04% fio [kernel.kallsyms] [k] ext4_file_read_iter Thanks, Ali